Chronic kidney disease (defined as roughly half of normal kidney function) is a common condition in the general population. Previous studies suggested that decreased kidney function is associated with impaired cognitive function or dementia, partly because chronic kidney disease and dementia have common risk factors such as smoking, socio-economic status, and diabetes mellitus. However, in the real-world practice, it is unknown how differently dementia is identified between patients with and without chronic kidney disease. Therefore, we will compare the proportion of patients with dementia diagnosis at one point (prevalence) and the rate of new dementia diagnosis (incidence) between patients with and without chronic kidney disease in UK primary care data. Results would be useful to understand the burden of dementia in patients with chronic kidney disease, and to discuss future healthcare-service planning for patients with chronic kidney disease.
We will compare the prevalence and incidence of dementia diagnosis between patients with and without chronic kidney disease (CKD). We will use a cohort of 242,349 matched pairs with and without CKD (estimated glomerular filtration rate <60 mL/min/1.73m2 twice for >3 months) for age, sex, general practice and calendar time between 2004 and 2014 in CPRD linked to Hospital Episode Statistics, which was established in our ongoing study (protocol 15_219RA). For prevalence, we will look at the dementia diagnosis recorded anytime after CPRD registration to the cohort entry (i.e. date of satisfying CKD definition for patients with CKD, and the same date for matched patients without CKD). For incidence, after excluding patients with prevalent dementia, we will compare the rate of a newly diagnosed dementia between patients with and without CKD. We will adjust for confounding factors including smoking and socio-economic status, care home residence, BMI, and comorbidities such as diabetes and cardiovascular diseases in the logistic regression analysis for prevalent dementia and Poisson regression analysis for incident dementia. We will also conduct subgroup analyses by dementia type (vascular dementia or Alzheimer’s disease), by CKD stage among patients with CKD, and by frequency of creatinine measurement among patients without CKD.
Dorothea Nitsch - Chief Investigator - London School of Hygiene & Tropical Medicine ( LSHTM )
Masao Iwagami - Corresponding Applicant - University of Tsukuba
Liam Smeeth - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
Masao Iwagami - Collaborator - University of Tsukuba
Rikako Hiramatsu - Collaborator - London School of Hygiene & Tropical Medicine ( LSHTM )
HES Admitted Patient Care;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation